Our latest intrusion of Arctic air into the region has been much kinder than earlier this winter: less wind, slightly warmer temperatures, and plenty of sunshine!Coincident with this intrusion, we recently received some really interesting pictures of a phenomenon you may have seen before: light pillars.What are light pillars, and how exactly are they formed?A light pillar is an atmospheric optical phenomena (belongs to the halo family), in which a vertical column of light appears to radiate directly above and/or below a light source. I use the phrase "light source" here because there are different types of sources that can create this phenomena. The pictures Janeen took in Plattsburgh show multi-colored pillars forming near artificial lights. The orange pillars form from sodium-vapor lights, and the white pillars from LED lights. You also might see similar columns of light at sunrise, sunset, or even near the moon!These are called sun/moon pillars. So how are they formed? Besides a light source, the main component to this impressive optical phenomenon are ice crystals suspended in the sky near the Earth's surface.As shown in the diagram above, millions of flat, hexagonal (plate) ice crystals are present when a pillar forms. In order for these crystals to linger just above the ground, it has to be quite cold outside (10°F or colder). These plates are oriented such that they act as tiny mirrors to reflect the light towards the viewer. The larger the ice crystals, the more impressive the light pillar becomes! Crystals found further up in the atmosphere make the pillar taller as well. Why do these pillars appear to extend directly above/below the light source, as seen in Janeen's pictures? Believe it or not, this is actually an optical illusion. Our eyes (even camera lenses) are tricked by the reflections, and we view this as shafts of light extending into the sky. Have a weather question, curious about a specific atmospheric phenomena? You can always contact me at eric.weglarz@hearst.com.

Our latest intrusion of Arctic air into the region has been much kinder than earlier this winter: less wind, slightly warmer temperatures, and plenty of sunshine!

Coincident with this intrusion, we recently received some really interesting pictures of a phenomenon you may have seen before: light pillars.

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Light Pillars | Plattsburgh, NY

What are light pillars, and how exactly are they formed?

A light pillar is an atmospheric optical phenomena (belongs to the halo family), in which a vertical column of light appears to radiate directly above and/or below a light source.

I use the phrase "light source" here because there are different types of sources that can create this phenomena.

The pictures Janeen took in Plattsburgh show multi-colored pillars forming near artificial lights.

The orange pillars form from sodium-vapor lights, and the white pillars from LED lights.

You also might see similar columns of light at sunrise, sunset, or even near the moon!

These are called sun/moon pillars.

So how are they formed?

Besides a light source, the main component to this impressive optical phenomenon are ice crystals suspended in the sky near the Earth's surface.

Ice Pillar Formation

As shown in the diagram above, millions of flat, hexagonal (plate) ice crystals are present when a pillar forms.

In order for these crystals to linger just above the ground, it has to be quite cold outside (10°F or colder).

These plates are oriented such that they act as tiny mirrors to reflect the light towards the viewer.

The larger the ice crystals, the more impressive the light pillar becomes!

Crystals found further up in the atmosphere make the pillar taller as well.

Why do these pillars appear to extend directly above/below the light source, as seen in Janeen's pictures?

Believe it or not, this is actually an optical illusion.

Our eyes (even camera lenses) are tricked by the reflections, and we view this as shafts of light extending into the sky.

Have a weather question, curious about a specific atmospheric phenomena? You can always contact me at eric.weglarz@hearst.com.